Max Perkins: Editor of Genius is reissued this month, 35 years after it was first published – but what can the man who told Ernest Hemingway to "tone it down" and lived to tell the tale teach us about publishing today?

Random House founder Bennett Cerf described a lunch in 1925 with Theodore Dreiser, author of An American Tragedy, and Horace Liveright, the book's first publisher. Liveright had struck a deal with Dreiser: if he sold film rights, Dreiser would receive a one-off payment of $50,000; if Liveright got more than that, the difference would be split 50/50. Liveright later handed Dreiser a cheque for $67,500 over lunch – only for Dreiser to storm out of the restaurant, accusing his publisher of ripping him off. "Bennett," Liveright told Cerf as he recalled the lunch, "let this be a lesson to you. Every author is a son of a bitch."

It was a very different time; a time of great publishers such as Liveright, Cerf and Charles Scribner's Sons, and a time of great writers, too. If F Scott Fitzgerald, Ernest Hemingway and Thomas Wolfe were the greatest novelists of their time, then Max Perkins – editorial director at Scribner, friend, personal banker and more to all three – was surely the greatest editor. Wolfe even said as much, before falling out with Perkins and the firm due to, shall we say, "artistic differences".

A century has passed since Perkins entered the publishing profession – and the book trade has had more ups and downs than Scott and Zelda's marriage. In our time, Steve Jobs has made the internet useable, Amazon has rendered the high street virtual – and with it has come the self-publishing bubble, the ebook, and the so-called death of the printed word. The role of the editor has been questioned by some, who believe agents now control the slush pile and therefore the next big thing – often perfecting a manuscript before it even reaches a publisher. Others champion the editor as a necessary gatekeeper and curator, hand-picking the Hemingways of tomorrow and protecting us from those destined to fail as novelists (and later to become critics, as Papa might say).

Don't believe the hype. With more books published (and printed) today than ever before, there's less to separate us from the Golden Age of Letters than one might think. Take editing, a job that still relies on the same basic principles Perkins himself swore by – even if the PDF has replaced the galley proof. "An editor does not add to a book," he argued. "At best he serves as a handmaiden to an author. Don't ever get to feeling important about yourself, because an editor at most releases energy. He creates nothing."

Perkins later simplified this inalienable truth, stating: "An editor should strive for anonymity." Though this is true of a text, it can't be so in life – for the periods in which a manuscript is begun and completed, or accepted, edited then published, are now and always have been replete with angst, neuroses and fitful bouts of self-loathing.

Especially if the writer has a drinking problem. When the agent Harold Ober wouldn't, or couldn't, bail out Fitzgerald any longer, Perkins stepped in – lending a man labelled a has-been in his 30s thousands of dollars a throw. Perkins never sought credit for being the best friend any author could ask for, because he also knew then what all editors can confirm today: when a book fails, a publisher gets the blame; when it's a success, a publisher is swiftly forgotten.

"I have a certain conception of what I conceive to be the right relationship between a writer and publisher," said novelist Sherwood Anderson, "a relationship that might be, at its best, a kind of intellectual marriage." When Anderson wrote this in one of his many letters to Perkins, he was speaking of a pact that continues to thrive – because there's simply no other way. An editor needn't like an author to fall passionately in love with their work; and vice versa. The relationship will be tempestuous, and often unrequited.